1. Field of the Invention
The present invention relates to a communication system for passenger vehicles and, more particularly, a system for providing satellite broadcasted video, and other signals, directly to passengers on passenger vehicles such as, for example, airplanes, boats and automobiles.
2. Background of the Invention
A major drawback of many types of radio communication systems is that their range is limited to radio horizon (radioelectric range by direct propagation). This drawback can only be obviated by the installation of relays between two stations situated out of radio range. Satellites can be used as relays, but this solution is still expensive when complete global coverage is required, as presently existing systems require that a large number of satellites be maintained in service in order for one or two satellites to be in view at every point on the globe.
One relay system for transmitting information between an emitting station and a receiving station that are separated by a distance exceeding the range of direct communications of these stations is disclosed in U.S. Pat. No. 5,530,909 to Simon et al. Simon discloses equipping aerodynes (e.g., airplanes) traveling in the space included between the two stations with open communications relay systems of limited range which can momentarily interconnect, when within range of one another, in order to pass information from relay system to relay system up to its destination.
Another relaying system using aircraft to relay an information signal to create an early warning system is disclosed in U.S. Pat. No. 2,571,386 to Sarnoff. Sarnoff describes forming a continuous line of relay transmission by flying a number of aircraft in a line, spaced such that direct communication between adjacent aircraft in the line is possible. Each aircraft serves as a relay link to maintain communication between stations at the ends of the line.
Thus, the systems described in Simon and Sarnoff, and other similar systems, use aircraft as relays to enable communication between two stations that are otherwise out of range of one another.